Given:
Mass of the rail road car, m = 2 kg
velocity of the three cars coupled system, v' = 1.20 m/s
velocity of first car, 
= 3 m/s
Solution:
a) Momentum of a body of mass 'm' and velocity 'v' is given by:
p = mv
Now for the coupled system according to law of conservation of momentum, total momentum of a system before and after collision remain conserved:
(1)
where,
= velocity of the first car
= velocity of the 2 coupled cars after collision
Now, from eqn (1)
v' = 1.80 m/s
Therefore, the velocity of the combined car system after collision is 1.80 m/s
1) A The 78g
2) C Push on the wagon in the opposite direction as Jack with a force that is the same as Jack is applying.
l will help and if you get it correctly I will say you are welcome
Answer:
a) No. If air resistance is ignored the acceleration of the ball is the same at each point on its flight.
(b). No. As long as the air resistance is negligible, the acceleration of the ball at the top of its flight different from its acceleration just before it lands.
Explanation:
This constant, similar acceleration is called the acceleration due to gravity and it is the acceleration of a body due to the influence of the pull of gravity alone.
Every object on the surface of the earth regardless of its mass is pulled towards the centre of the earth, especially when in flight. Whether flying upwards, or coming downwards, the pull of attraction towards the surface of the earth is the same!
